Handpiece for dental engines.



PATENTED NOV. 12, 1907.

J. F. HARDY. HANDPIEGE POR'DENTAL ENGINES.

. APPLICATION FILED MAR. 9, 1906.

lill/1151' ill/heffen UNITED sTATEs PATENT oEEicE.

JAMES F. HARDY, OF NEW YORK, N. Y., ASSIGNOR TO CONSOLIDATED DENTAL MANUFACTURING COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

HANDPIECE FOR DENTAL ENGINES.

Specification of Letters Patentp Patented Nov. 12, 1907.

To all whom 'it may concern:

Be it known that I, JAMES F. HARDY, a citizen of the United States, and a resident of the borough of Manhattan, in the city and State of New York, have invented a new and useful Handpiece for Dental Engines, of which the following is a specification.l

My invention relates to hand pieces for dental engines and more particularly to means for locking and releasing the tool chuck and for adjusting the parts of the shell within which the spindle revolves to prevent the latter from wabbling or chattering during operation, and, at the same time, permit the ready removal of the casing for cleaning and oiling.

In the accompanying drawings, Figure 1 is a View of the hand piece in side elevation, Fig. 2 is a view of the same in longitudinal section showing the tool holding Chuck in its released position, Fig. 3 is a partial longitudinal section showing the tool holding chuck in its closed position, Fig` 4 is a view of the spindle in side elevation, in detail, Fig. 5 is a transverse section in the plaire of the line A-A of Fig. 1, Fig. 6 is a partial longitudinal section showing the means for adjusting the casing sections with respect to one another, Fig. 7 is a view in detail of the slide for operating the chuck opening and closing lever, the same being partially broken away to show the position of the graduated lever operating dog, Fig. 8 is an end view of the same, Fig. 9 is a view in detail of the lever for locking and releasing the chuck, Fig. 10 is a view in detail of the bar for transmitting the action of the lever to the chuck, showing the same in longitudinal section, Fig. 11 is an end view of the same, and Fig. 12 is a view in detail of one of the arms for operating the slide which controls the chuck operating lever..

The casing consists of a part 1 which is grasped by hand of the operator in handling the tool, a part 2 having a telescopic connection with the part 1 and a part 3 for housing the mechanism for attaching the flexible shaft to the spindle.

The rotary spindle consistsof a tubular forward portion 4 conveniently connected by a screw threaded engagement with a tubular rear portion 5, the latter having an extended tang 6 which has a rotary bearing within the part 2 of the casing and extends thence into the part 3 for the attachment of the driving mechanism. The chuck is denoted by 7. It consists of a split sleeve as usual, its forward end being received in the forward tapered end of the part 4 of the hollow spindle and its rear end being beveled as shown at 8 to fit in a conical socket in the end of an intermediate piece 9 which ispressed toward the chuck by a block 10, the latter being in turn acted upon by the longitudinally sliding bar 11 seated within the part 5 of the spindle, and controlled by the rocking lever 12.

The rocking lever 12 has, at one end, a heel 13 and toe 14, the heel being arranged to bear against the end wall of the bore within the tubular portion 5 of the spindle and the toe 14 being arranged to engage a lug 15011 the chuck operating bar 1l. From the heel and toe end of the lever 12 an arm extends forwardly and its extreme end is bent to engage a series of notches 1G on the inclined face of the dog 17.

The dog 17 is a part of or fixed rigidly with respect to a short sliding sleeve 1S located within the part l ofthe casing and surrounds part 5 of the spindle, the dog 17, see Figs. 7 and 8, extends inwardly from the interior Wall of the sleeve through a slot 19 in the spindle into position to engage the end of the lever 12 as aforesaid, the latter being free to rock in a narrow slot 20 formed in the bar l1.

The inner face of the dog has the shallowest portion of the incline forward and the several notches in its face are so rounded that while the end of the lever 12 will be held therein against accidental displacement, the dog may be forced either forwardly or rearwardly by applying stress thereto for the purpose of rocking the lever l2 more or less.

The sleeve 18 and hence the incline faced dog 17 carried thereby may be slid longitudinally by means of a pair of thin arms 2l, 22, seated in the opposite sides of the part 2 of the casing and extending within part 1 of the casing, their free ends being provided with shallow inwardly extendingv lugs 23, 24, for engaging an annular groove 25 formed in the exterior wall ofthe sleeve.

To permit the arms to pass the rear end of the sleeve, the said end is made the thickness of thc arms 21 or 22 less in diameter than the body portion, this reduced portion being indicated at 2G, Fig. 7.

The arms 2l, 22, are attached by means of screws 27, 28, to an annular collar 29 and by sliding this collar along the part 2 of the casing, the sleeve 18 may be slid in the one direction or the other to rock the lever 12 and hence to operate the chuck, and this sliding movement is independent of the spindle.

lt is to be noted that the sleeve 18, its dog 17, together with the operating lever 12 and bar 11, are free to rotate with the spindle, while, at the same time, the sleeve may be adjusted longitudinally and the lever rocked laterally to slide the bar 11.

By providing the inclined face of the dog' 17 with a series of notches at different distances from the axis of the spindle, the lever 12 may be rocked to a greater or less extent to give the desired grip on the tool whether its shank be a little less in diameter or a little greater in diameter than the normal and also to take up any Wear which may occur from the frequent rocking of the lever or the sliding of the parts.

For adjusting the parts 1 and 2 of the casing with respect to each other, l provide the part 2with a collar 30 formed integral therewith, or fixed thereon in proximity to the rear end of the part l and set in the end oi the part 1 a screw 31, the head of which bears against the face of the collar 30 to hold the latter. and hence the part 2, in the desired position.

By turning the screw 3l into the end of the part 1 of the casing, the part 2 may be slid inwardly into engagement with the end of the screw or by turning the screw out, the part 2 may be held in that position by its engagement with the screw, the tWo parts being finally locked in their adjusted position by means of a set screyi7 32 extending through the part l into engagement with the part 2.

The structure admits of the removal of the part l of the casing, at pleasure, Without disturbing the chuck controlling collar 29 which slides along the part 2 of th casing.

What I claim is:

In a dental hand piece, the combination with a rotary spindle, a casing inclosing the spindle consisting of telescoping sections, the spindle having an extended hearing centrally along one of said casing sections and the other casing section being removable over the tool carrying end of the spindle, a chuck located Within the spindle and constructed to expand and contract, a sliding har located Within the spindle, a rocking lever housed Within the sliding bar and fulcruming on the interior of the spindle for operating the sliding bar, movable means mounted in the spindle intermediate of said bar and chuck for operating the latter, a sleeve surrounding the said sliding bar and provided with an inclined faced dog and extending into engagement with the rocking lever Within the slidingl bar, arms extending along the exterior of one of the casing sections and engaged with said sliding sleeve and a collar surrounding the casing -and connected With the said arms for operating them and hence the sleeve carrying dog and lever.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two Witnesses. this 16th day of February, 1906.

JAMES F. HARDY.

Witnesses H. D. BULTMAN, J. F. BBOMMER. 

